The proposed research effort is primarily concerned with the long range goal of better understanding the role of glutathione in ocular tissues, especially the lens. The role of glutathione in the lens will be examined by isolation and study of the individual enzymes of the gamma-glutamyl cycle, by study of the enzymes in cultured lens preparations, and by experiments designed to test whether or not the gamma-glutamyl cycle is intimately linked with amino acid transport in the lens.